Andrew Wolf, 41, was arrested on Thursday and is facing multiple counts of possessing and distributing child pornography. FBI agents also raided his home in the Roxborough section of Philadelphia on Thursday.
"I thought no way, he's just our neighbor. So it's definitely a little creepy, especially given his occupation," said neighbor Nina Perala.
According to the criminal complaint filed by the FBI, the photo-sharing company Dropbox sent police a tip that alleges Wolf used his school email address to upload suspected child pornography onto his account.
After executing a search warrant, officials say they discovered Wolf had three files depicting sexually explicit images or videos of minors.
"It's surprising, it's very disturbing actually," said neighbor Marshall Gould. "It's a quiet neighborhood, there's a lot of kids in this neighborhood. It's just, it's a lot to take in right now but it's very disturbing. I don't feel too good about it."
Officials also allege Wolf used social media like Instagram to pay minors for sexually explicit videos. The criminal complaint details at least six attempts to purchase the videos of a victim for $100.
The FBI said Wolf's profile photo was of a teenage girl who also appears to be underage.
"It's kind of surprising to hear that," said neighbor Tom Madonna. "It's kind of awful to hear knowing it's right next door. I have two kids of my own and knowing he has a child too, that's kind of heartbreaking really."
The criminal complaint says Wolf lives alone with his six-month-old child.
Wolf's attorney did not reply when asked for comment. Wolf has a detention hearing scheduled for Tuesday.
In a statement, Springside Chestnut Hill Academy said:
"We are all unsettled and upset by this news and acted immediately to inform our community of the situation as well as put Mr. Wolf on administrative leave. We do not anticipate his return. We are working closely with the FBI on their investigation, which was prompted by activity that occurred outside of SCH, over the summer and while Mr. Wolf was on parental leave. Springside Chestnut Hil Academy has absolutely no tolerance for such activity and is unyielding in its commitment to the safety of our students."
When 6abc asked if Mr. Wolf had any inappropriate contact with a student, the school spokesperson said: "We have no knowledge of any SCH student having this kind of contact with Wolf, but any questions about details regarding Wolf's activity need to be directed to the FBI because this is an active investigation and we are working closely with the FBI."